Abstract: The present invention relates to a method of installing an electrical earthing system, comprising: determining a borehole site, providing a drill string comprised of a conductive material and having a drill bit at an end thereof, and electrically connecting the drill string to an earth test terminal of a resistance testing apparatus, electrically connecting a test electrode or electrodes to a remaining terminal or terminals of the resistance testing apparatus and placing the test electrode(s) around the borehole, drilling the borehole using the drill string, periodically or continuously measuring and recording a total electrical resistance using the resistance testing apparatus, and adjusting the drill string to reduce the total electrical resistance towards a target total electrical resistance, removing the drill rod from the borehole and disconnecting the drill string from the resistance testing apparatus, installing an earthing electrode within the borehole, and backfilling the borehole with backfill groun